1. Field of the Invention
This invention relates to a flame detecting and alarming system with a ultraviolet sensor. The system detects an ultraviolet radiation from a flame, which may be of matches, a lighter, a burner, a fire, or any flammable object, and generates an alarming sound. The system is typically used for a fire alarm system.
2. Description of the Prior Art
There have been various kinds of fire alarm systems in the market. Among them is a system that detects ultraviolet rays radiated from a flame and triggers an alarming sound.
However many of the conventional fire alarming systems have some of the following disadvantages:
(1) The horizontal and vertical fire-detectable angles as viewed from the detector are too narrow. The fire-detectable distance is too short. Some systems can detect a fire within only a few meter range. Some systems can detect a fire not in its initial stage but only after the fire has developed to a critical stage. PA1 (2) Some systems are operable only on an AC power. Therefore, the systems can not be used where no commercial power is available. The requirement for a power-supply transformer makes the system bulky and heavy and, thus, the locations where the systems can be installed have to be limited. PA1 (3) An alarm sound does not reach distant places. PA1 (4) An alarm sound is too weak to be heard where a high-level background noise is present.